vines.register_vine = function( name, defs, biome )
  --different properties for bottom and side vines.
  local drop_node = 'vines:'..name
  local drawtype = ''
  local selection_box
  local groups = { vines=1, snappy=3, flammable=2 }

  local group_name = name..'_vines'
  biome.spawn_surfaces[ #biome.spawn_surfaces ] = group_name

  if ( biome.spawn_on_side ) then
    selection_box = {
      type = "wallmounted",
    }
    drawtype = 'signlike'
  else
    selection_box = {
      type = "fixed",
      fixed = { -0.4, -1/2, -0.4, 0.4, 1/2, 0.4 },
    }
    drawtype = 'plantlike'
  end

  biome.spawn_plants = { "vines:"..name }

  minetest.register_node( "vines:"..name, {
    description = defs.description,
    walkable = false,
    climbable = true,
    wield_image = "vines_"..name..".png",
    drop = "",
    sunlight_propagates = true,
    paramtype = "light",
    paramtype2 = "wallmounted",
    buildable_to = true,
    tile_images = { "vines_"..name..".png" },
    drawtype = drawtype,
    inventory_image = "vines_"..name..".png",
    groups = groups,
    sounds = default.node_sound_leaves_defaults(),
    selection_box = selection_box,
    on_construct = function( pos )
      local timer = minetest.get_node_timer( pos )
      timer:start( math.random(5, 10) )
    end,
    on_timer = function( pos )
      local node = minetest.get_node( pos )
      local bottom = {x=pos.x, y=pos.y-1, z=pos.z}
      local bottom_node = minetest.get_node( bottom )
      if bottom_node.name == "air" then
        if not ( math.random( defs.average_length ) == 1 ) then
          minetest.set_node( pos, { name = node.name..'_rotten', param2 = node.param2 } )
          minetest.set_node( bottom, { name = node.name, param2 = node.param2 } )
          local timer = minetest.get_node_timer( bottom_node )
          timer:start( math.random(5, 10) )
        end
      end
    end,
    after_dig_node = function(pos, node, oldmetadata, user)
      vines.dig_vine( pos, drop_node, user )
    end
  })

  local name = name..'_rotten'

  minetest.register_node( "vines:"..name, {
    description = "Rotten "..defs.description,
    walkable = false,
    climbable = true,
    drop = "",
    sunlight_propagates = true,
    paramtype = "light",
    paramtype2 = "wallmounted",
    buildable_to = true,
    tile_images = { "vines_"..name..".png" },
    wield_image = "vines_"..name..".png",
    drawtype = drawtype,
    inventory_image = "vines_"..name..".png",
    groups = groups,
    sounds = default.node_sound_leaves_defaults(),
    selection_box = selection_box,
    on_destruct = function( pos )
      local node = minetest.get_node( pos )
      local bottom = {x=pos.x, y=pos.y-1, z=pos.z}
      local bottom_node = minetest.get_node( bottom )
      if minetest.get_item_group( bottom_node.name, "vines") then
        minetest.remove_node( bottom )
      end
    end,
    after_dig_node = function( pos, node, oldmetadata, user )
      vines.dig_vine( pos, drop_node, user )
    end
  })

  plantslib:spawn_on_surfaces( biome )

  local override_nodes = function( nodes, defs )
    function override( index, registered )
      local node = nodes[ index ]
      if index > #nodes then return registered end
      if minetest.registered_nodes[node] then
        minetest.override_item( node, defs )
        registered[#registered+1] = node
      end
      override( index+1, registered )
    end
    override( 1, {} )
  end

  override_nodes( biome.spawn_surfaces,{
    after_destruct = function( pos )
      local pos_min = { x = pos.x -1, y = pos.y - 1, z = pos.z - 1 }
      local pos_max = { x = pos.x +1, y = pos.y + 1, z = pos.z + 1 }
      local positions = minetest.find_nodes_in_area( pos_min, pos_max, "group:vines" )
      for index, position in pairs(positions) do
        minetest.remove_node( position )
      end
    end
  })

end

vines.dig_vine = function( pos, node_name, user )
  --only dig give the vine if shears are used
  if not user then return false end
  local wielded = user:get_wielded_item()
  if 'vines:shears' == wielded:get_name() then 
    local inv = user:get_inventory()
    if inv then
      inv:add_item("main", ItemStack( node_name ))
    end
  end
end
